// 图表相关功能
const WeatherChart = {
    chart: null,

    // 显示图表
    display(historyData = [], forecastData = []) {
        // 确保数据是数组
        historyData = Array.isArray(historyData) ? historyData : [];
        forecastData = Array.isArray(forecastData) ? forecastData : [];
        
        // 如果没有任何数据，则不绘制图表
        if (historyData.length === 0 && forecastData.length === 0) {
            return;
        }
        
        // 合并历史数据和预报数据的时间轴
        const allLabels = [...new Set([
            ...historyData.map(item => item.date_time),
            ...forecastData.map(item => item.date_time)
        ])].sort();

        // 准备历史数据
        const historyTemperatures = allLabels.map(label => {
            const item = historyData.find(d => d.date_time === label);
            return item ? item.temperature : null;
        });
        const historyHumidities = allLabels.map(label => {
            const item = historyData.find(d => d.date_time === label);
            return item ? item.humidity : null;
        });
        const historyRainfalls = allLabels.map(label => {
            const item = historyData.find(d => d.date_time === label);
            return item ? item.rainfall : null;
        });

        // 准备预报数据
        const forecastTemperatures = allLabels.map(label => {
            const item = forecastData.find(d => d.date_time === label);
            return item && item.temperature !== null ? item.temperature : null;
        });
        const forecastRainfalls = allLabels.map(label => {
            const item = forecastData.find(d => d.date_time === label);
            return item && item.rainfall !== null ? item.rainfall : null;
        });

        // 销毁旧图表
        if (this.chart) this.chart.destroy();

        // 创建数据集
        const datasets = [
            {
                label: '温度 (°C) - 实测',
                data: historyTemperatures,
                borderColor: 'rgb(255, 99, 132)',
                backgroundColor: 'rgba(255, 99, 132, 0.1)',
                yAxisID: 'y-temperature',
                tension: 0.4,
                spanGaps: false
            },
            {
                label: '湿度 (%) - 实测',
                data: historyHumidities,
                borderColor: 'rgb(54, 162, 235)',
                backgroundColor: 'rgba(54, 162, 235, 0.1)',
                yAxisID: 'y-humidity',
                tension: 0.4,
                hidden: true,
                spanGaps: false
            },
            {
                label: '雨量 (mm) - 实测',
                data: historyRainfalls,
                type: 'bar',
                backgroundColor: 'rgba(54, 162, 235, 0.6)',
                borderColor: 'rgb(54, 162, 235)',
                yAxisID: 'y-rainfall'
            }
        ];

        // 添加预报数据集
        if (forecastData.length > 0) {
            datasets.push(
                {
                    label: '温度 (°C) - 预报',
                    data: forecastTemperatures,
                    borderColor: 'rgb(255, 165, 0)',
                    backgroundColor: 'rgba(255, 165, 0, 0.1)',
                    borderDash: [5, 5],
                    yAxisID: 'y-temperature',
                    tension: 0.4,
                    spanGaps: false
                },
                {
                    label: '雨量 (mm) - 预报',
                    data: forecastRainfalls,
                    type: 'bar',
                    backgroundColor: 'rgba(255, 165, 0, 0.4)',
                    borderColor: 'rgb(255, 165, 0)',
                    yAxisID: 'y-rainfall'
                }
            );
        }

        // 创建组合图表
        const ctx = document.getElementById('combinedChart').getContext('2d');
        this.chart = new Chart(ctx, {
            type: 'line',
            data: {
                labels: allLabels,
                datasets: datasets
            },
            options: {
                responsive: true,
                maintainAspectRatio: false,
                interaction: {
                    mode: 'index',
                    intersect: false,
                },
                scales: {
                    'y-temperature': {
                        type: 'linear',
                        display: true,
                        position: 'left',
                        title: {
                            display: true,
                            text: '温度 (°C)'
                        }
                    },
                    'y-humidity': {
                        type: 'linear',
                        display: true,
                        position: 'right',
                        title: {
                            display: true,
                            text: '湿度 (%)'
                        },
                        grid: {
                            drawOnChartArea: false
                        },
                        min: 0,
                        max: 100
                    },
                    'y-rainfall': {
                        type: 'linear',
                        display: true,
                        position: 'right',
                        title: {
                            display: true,
                            text: '雨量 (mm)'
                        },
                        grid: {
                            drawOnChartArea: false
                        },
                        beginAtZero: true
                    }
                }
            }
        });
    }
};

// 导出图表对象
window.WeatherChart = WeatherChart;